Forming electrochromic stacks using at most one metallic lithium deposition station

ABSTRACT

The present disclosure describes various processes of forming an electrochromic stack using at most one metallic lithium deposition station. In some aspects, a process may include depositing metallic lithium only within an electrochromic counter-electrode of an electrochromic stack. In some aspects, a process may include using a lithium-containing ceramic counter-electrode target to form an electrochromic counter-electrode and depositing metallic lithium only within or above an electrochromic electrode of the electrochromic stack. In some embodiments, a process may include using a lithium-containing ceramic electrode target, and optionally additionally depositing metallic lithium to add mobile lithium to the electrochromic stack. In some embodiments, a process may include using a single metallic lithium deposition station to deposit metallic lithium between an ion-conducting layer and an electrochromic electrode of the electrochromic stack.

This application is a continuation from U.S. patent application Ser. No.17/172,960, filed Feb. 10, 2021, which claims benefit of priority toU.S. Provisional Application Ser. No. 62/975,625, filed Feb. 12, 2020,which are hereby incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure is directed to electrochromic stacks, and moreparticularly to processes of forming electrochromic stacks using at mostone metallic lithium deposition station.

BACKGROUND

An electrochromic device helps to block the transmission of visiblelight and keep a room of a building or passenger compartment of avehicle from becoming too warm. Electrochromic stacks may bemanufactured by sputtering thin film layers by physical vapordeposition, including metallic lithium. Because metallic lithium isextremely inflammable in contact with water, it can only be sputtered inspecially engineered sputtering compartments, engineered to be isolatedfrom the rest of the process and, contrary to the vast majority ofmagnetron chambers, not cooled by water. This makes the inclusion oflithium sputtering compartments into a coater very expensive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts electrochromic electrodes and counter-electrodes with andwithout deposited metallic lithium after heat tempering, according tosome embodiments.

FIG. 2 is a flow diagram depicting an example of a process of forming anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium within a counter-electrode layer ofthe electrochromic stack, according to some embodiments.

FIG. 3 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 2 , according tosome embodiments.

FIG. 4 is a flow diagram depicting an example of a process of forming anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium onto an electrochromic electrodelayer and utilizing a lithium-containing ceramic target to form acounter-electrode layer of the electrochromic stack, according to someembodiments.

FIG. 5 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 4 , according tosome embodiments.

FIG. 6 is a flow diagram depicting an example of a process of forming anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium within an electrochromic electrodelayer and utilizing a lithium-containing ceramic target to form acounter-electrode layer of the electrochromic stack, according to someembodiments.

FIG. 7 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 6 , according tosome embodiments.

FIG. 8 is a flow diagram depicting an example of a process of forming anelectrochromic stack with no metallic lithium stations by utilizinglithium-containing ceramic targets to form an electrochromic electrodelayer and a counter-electrode layer of the electrochromic stack,according to some embodiments.

FIG. 9 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 8 , according tosome embodiments.

FIG. 10 is a flow diagram depicting an example of a process of formingan electrochromic stack that includes utilizing a lithium-containingceramic target to form an electrochromic electrode layer of theelectrochromic stack and utilizing a single metallic lithium station todeposit metallic lithium onto a counter-electrode layer of theelectrochromic stack, according to some embodiments.

FIG. 11 is a block diagram depicting various layers of theelectrochromic stack formed according to the process depicted in FIG. 10, according to some embodiments.

FIG. 12 is a flow diagram depicting an example of a process of formingan electrochromic stack that includes utilizing a single metalliclithium station to deposit metallic lithium between an ion-conducting(IC) layer and an electrode layer of the electrochromic stack, accordingto some embodiments.

FIG. 13 is a block diagram depicting various layers of theelectrochromic stack formed according to the process depicted in FIG. 12, according to some embodiments.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements of the figures maybe exaggerated relative to other elements to help to improveunderstanding of embodiments of the invention.

DETAILED DESCRIPTION

The present disclosure describes a method to obtain an electrochromicstack while depositing metallic lithium in at most one deposition step(e.g., in at most one station), thus saving costs compared to solutionsrequiring two or more lithium deposition steps/stations. In someembodiments, a process may include depositing metallic lithium onlywithin an electrochromic counter-electrode (also referred to herein as a“counter-electrode”) of an electrochromic stack. In some embodiments, aprocess may include using a lithium-containing ceramic counter-electrodetarget (e.g., a mixed Li:Ni:W ceramic target) to form acounter-electrode and depositing metallic lithium only within or abovean electrochromic electrode (also referred to herein as an “electrode”)of the electrochromic stack. In some embodiments, a process may includeusing lithium-containing ceramic electrode target, and optionallyadditionally depositing metallic lithium to add mobile lithium to theelectrochromic stack (e.g., in cases where the counter-electrode targetis not a lithium-containing mixed target). In some embodiments, aprocess of forming an electrochromic stack using a single metalliclithium deposition station may including depositing a counter-electrode,an ion-conducting (IC) layer, and metallic lithium above the IC layerand below an electrode. Advantages associated with the variousembodiments of the present disclosure include reducing a number oflithium sputtering compartments, which provides cost savings, improvedsafety, and more flexibility in the manufacturing process.

A manufacturing process for an electrochromic stack typically involvesone or several steps of thermal treatment after layer deposition thatcrystallizes indium tin oxide (ITO) used as conductive material and thattriggers a partial crystallization of the electrode andcounter-electrode. Prior to experimentation, it was the inventors'understanding that it was desirable to have lithium present in both theelectrode and counter-electrode prior to the thermal treatment step, inorder to optimize the electrochemical properties for both, for instancethe amount of mobile charge that they can accommodate. However, theinventors have observed that experimental results have shown that as thetemperature of the thermal treatment increases, it is desirable to lowerthe amount of lithium present in the counter-electrode. This helpsmaximize the amount of mobile lithium that each electrode canaccommodate after the thermal treatment, hence the amount of charge thatcan be exchanged between the electrode and the counter-electrode, andthe contrast between the clear/bleached and tinted states. Varying thetemperature may be desirable for several purposes. For instance, in somecases, increased mechanical resistance of the glass substrate may beobtained by tempering the coated glass at high temperature. In othercases, a bus bar frit is applied to the coated glass prior to firing,and the firing temperature may be adjusted to maximize the fritconductivity.

Hence, the inventions described herein may have various benefits. Onepotential benefit is allowing manufacture of electrochromic coatingswith only one metallic lithium sputtering compartment in the process.Another potential benefit is introducing flexibility in the process sothat, for instance, an electrochromic stack to be laminated and anotherelectrochromic stack to be tempered can be manufactured on the sameproduction line.

In each of the embodiments of the invention, metallic lithium can bedeposited in a single deposition compartment through various types ofphysical vapor deposition. A first example of physical vapor depositionis evaporation of lithium. This method includes heating lithiumgranulates to their boiling temperature in order to deposit lithium onthe substrate by evaporation. This method may provide severaladvantages. One advantage is allowing to reach substantial depositionrates (e.g., greater than 100 nm/min versus 10-30 nm/min in a standardmagnetron sputtering process). Another advantage is increasing theuptime and reducing maintenance time, since no opening of the lithiumcompartment is required to feed the process with lithium. A secondexample of physical vapor deposition is magnetron sputtering of lithium.In a particular embodiment of a magnetron sputtering configuration,rotary targets are used (instead of planar targets) to maximize materialuse and increase deposition rates. Lithium targets may be cooled with anon-water-based liquid coolant (e.g., oil) in order to preventaccidental reaction of lithium with water in the event of a leak.Adjustable magnet bars may be used to improve the lithium homogeneity,being more precise than trim with sputtering gases (a typical technique)and safer than use of adjustable masks that create areas where metalliclithium can accumulate (requiring frequent cleaning).

The following description in combination with the figures is provided toassist in understanding the teachings disclosed herein. The followingdiscussion will focus on specific implementations and embodiments of theteachings. This focus is provided to assist in describing the teachingsand should not be interpreted as a limitation on the scope orapplicability of the teachings.

As used herein, the term “comprises,” “comprising,” “includes,”“including,” “has,” “having,” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of features is notnecessarily limited only to those features but may include otherfeatures not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive-or and not to an exclusive-or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

The use of “a” or “an” is employed to describe elements and componentsdescribed herein. This is done merely for convenience and to give ageneral sense of the scope of the invention. The description should beread to include one or at least one and the singular also includes theplural, or vice versa, unless it is clear that it is meant otherwise.

The use of the word “about”, “approximately”, or “substantially” isintended to mean that a value of a parameter is close to a stated valueor position. However, minor differences may prevent the values orpositions from being exactly as stated. Thus, differences of up to tenpercent (10%) for the value are reasonable differences from the idealgoal of exactly as described.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples are illustrative only and not intended to be limiting. To theextent not described herein, many details regarding specific materialsand processing acts are conventional and may be found in textbooks andother sources within the glass, vapor deposition, and electrochromicarts.

The embodiments as illustrated in the figures and described below helpin understanding particular applications for implementing the conceptsas described herein. The embodiments are exemplary and not intended tolimit the scope of the appended claims.

FIG. 1 illustrates capacity and contrast of tempered electrochromicelectrodes and counter-electrodes. The stacks depicted in the topportion of FIG. 1 correspond to tempered electrodes, and the stacksdepicted in the bottom portion of FIG. 1 correspond to temperedcounter-electrodes.

Referring to the tempered electrodes in the top portion of FIG. 1 , theleft stack illustrates ITO/WO_(x) (i.e., with no metallic Li depositedonto the WO_(x) layer) after heat tempering at about 650° C. for about 5minutes; and the right stack illustrates ITO/WO_(x)/Li (i.e., withmetallic Li deposited onto the WO_(x) layer) after heat tempering atabout 650° C. for about 5 minutes. For the particular examples depictedin FIG. 1 , the inventors determined that the tempered electrode with nometallic Li deposited (left side stack) had a charge capacity of 65mC/cm² and a contrast of 14. By comparison, the inventors determinedthat the tempered electrode with metallic Li deposited (right sidestack) had a charge capacity of 5 mC/cm² and a contrast of 2.2. Thus,for a thermal treatment at a relatively high temperature of about 650°C., the inventors have determined that the presence of lithium isdetrimental to the electrochromic activity of the tempered electrode.

Referring to the tempered counter-electrodes in the bottom portion ofFIG. 1 , the left stack illustrates ITO/NiWO_(x) (i.e., no metallic Lideposited onto the NiWO_(x) layer) after heat tempering at about 650° C.for about 5 minutes; and the right stack illustrates ITO/NiWO_(x)/Li(i.e., metallic Li deposited onto the NiWO_(x) layer) after heattempering at about 650° C. for about 5 minutes. For the particularexamples depicted in FIG. 1 , the inventors determined that the temperedcounter-electrode with no metallic Li deposited (left side stack) had acharge capacity of about 0 mC/cm² and a contrast of about 1. Bycomparison, the inventors determined that the tempered counter-electrodewith metallic Li deposited (right side stack) had a charge capacity of15 mC/cm² and a contrast of 4.5. Thus, for a thermal treatment at arelatively high temperature of about 650° C., the inventors havedetermined that the presence of lithium is favorable to theelectrochromic activity of the tempered counter-electrode.

FIG. 2 is a flow diagram depicting an example of a process of forming anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium within a counter-electrode layer ofthe electrochromic stack, according to some embodiments

In FIG. 2 , metallic lithium is sputtered “within” thecounter-electrode. As illustrated and further described herein withrespect to FIG. 3 , a first portion of the counter-electrode may besputtered before the metallic lithium (e.g., corresponding to athickness of X nm), and a second portion of the counter-electrode may besputtered after the metallic lithium (e.g., corresponding to a thicknessof 270-X nm), according to some embodiments. Tuning the thickness of thecounter-electrode “below” the metallic lithium in the electrochromicstack versus the thickness sputtered “above” the metallic lithium in theelectrochromic stack allows for tuning the amount of lithium thatdiffuses to the WO_(x) electrode during the firing process and allowsfor adapting the stack to different firing conditions.

The configuration depicted in FIG. 2 has an advantage of offeringsubstantial flexibility. For instance, if non-temperable stacks andto-be-tempered stacks are manufactured on the same production line, thestacks may be submitted to substantially different heat treatments. Toillustrate, non-temperable stacks may be submitted to heat treatment atabout 400° C., while to-be-tempered stacks may be submitted to heattreatment at about 700° C. The position of the metallic lithium in thecounter-electrode can be adjusted accordingly by varying the depositionpower used in each of the counter-electrode deposition stations,according to some embodiments.

FIG. 2 illustrates a sequence of stations that may be used to form anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium within a counter-electrode layer ofthe electrochromic stack.

An underlayer station 202 may be used to form an underlayer of anelectrochromic stack. In some embodiments, the underlayer station 202may be used to an underlayer that includes multiple materials. Toillustrate, the underlayer station 202 may be used to form one portionof the underlayer from one material and another portion of theunderlayer from a different material. As an illustrative, non-limitingexample, the first portion of the underlayer formed at the underlayerstation 202 may correspond to a first layer of a first material (e.g.,Nb₂O₅) with a first thickness according to an electrochromic stackdesign. The second portion of the underlayer formed at the underlayerstation 202 may correspond to a second layer of a second material (e.g.,SiO₂) with a second thickness according to the electrochromic stackdesign.

Proceeding from the underlayer station 202, FIG. 2 illustrates that afirst conductive layer station 204 may be used to form a firstconductive layer of the electrochromic stack. In a particularembodiment, the first conductive layer station 204 may be used to forman indium tin oxide (ITO) layer with a particular thickness according tothe electrochromic stack design.

Proceeding from the first conductive layer station 204, FIG. 2illustrates that an electrode station 210 may be used to form anelectrochromic electrode (EC) layer of the electrochromic stack. In theparticular embodiment depicted in FIG. 2 , the electrode station 210utilizes a tungsten (W) target 212 to form a WO_(x) EC layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the electrode station 210, FIG. 2 illustrates that, insome embodiments, an ion-conducting (IC) station 220 may be used to forman IC layer of the electrochromic stack. In a particular embodiment, theIC station 220 may be used to form SiO_(x) layer with a particularthickness according to the electrochromic stack design. In alternativeembodiments, as indicated by the dashed lines in FIG. 2 , the IC station220 may be omitted.

Proceeding from the IC station 220 (or from the electrode station 210 incases where the IC station 220 is omitted), FIG. 2 illustrates that afirst counter-electrode station 230 may be used to form a first portionof a counter-electrode (CE) layer of the electrochromic stack. In theexample depicted in FIG. 2 , the first counter-electrode station 230utilizes a mixed nickel-tungsten (Ni:W) target 232 to form the firstportion of the CE layer with a first thickness. As described furtherherein, the first thickness may be determined based on various factors,including the particular electrochromic stack design and the particularfiring conditions such that a satisfactory amount of metallic lithiumdiffuses to the WO_(x) EC layer (formed at the electrode station 210)during the firing process.

Proceeding from the first counter-electrode station 230, FIG. 2illustrates that a single metallic lithium station 233 may be used todeposit a layer of metallic lithium onto the first portion of the CElayer. A thickness of the layer of metallic lithium may be determinedbased on various factors, including the particular electrochromic stackdesign and the particular firing conditions such that a satisfactoryamount of the metallic lithium diffuses to the WO_(x) EC layer (formedat the electrode station 210) during the firing process.

Proceeding from the single metallic lithium station 233, FIG. 2illustrates that a second counter-electrode station 236 may be used toform a second portion of the CE layer of the electrochromic stack. Inthe example depicted in FIG. 2 , the second counter-electrode station236 utilizes a mixed nickel-tungsten (Ni:W) target 238 to form thesecond portion of the CE layer with a second thickness. As describedfurther herein, the second thickness may be determined based on variousfactors, including the particular electrochromic stack design and theparticular firing conditions such that a satisfactory amount of metalliclithium (deposited at the metallic lithium station 233) diffuses to theWO_(x) EC layer (formed at the electrode station 210) during the firingprocess.

Tuning the thickness of the first portion of the CE layer (formed at thefirst CE station 230) that is “below” the metallic lithium (formed atthe metallic lithium station 233) in the electrochromic stack versus thethickness of the second portion of the CE layer (formed at the second CEstation 236) that is “above” the metallic lithium in the electrochromicstack allows for tuning the amount of lithium that diffuses to theWO_(x) EC layer (formed at the electrode station 210) during the firingprocess and allows for adapting the stack to different firingconditions. To illustrate, non-temperable stacks may be submitted toheat treatment at about 400° C. By contrast, to-be-tempered stacks maybe submitted to heat treatment at about 700° C. The position of themetallic lithium in the counter-electrode can be adjusted accordingly byvarying the deposition power used in each of the counter-electrodedeposition stations 230 and 236, according to some embodiments.

Proceeding from the second counter-electrode station 236, FIG. 2illustrates that a second conductive layer station 240 may be used toform a second conductive layer of the electrochromic stack. In aparticular embodiment, the second conductive layer station 240 may beused to form an ITO layer with a particular thickness according to theelectrochromic stack design.

Proceeding from the second conductive layer station 240, FIG. 2illustrates that an overlayer station 242 may be used to form anoverlayer of the electrochromic stack. In a particular embodiment, theoverlayer station 242 may be used to form a SiO_(x) layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the overlayer station 242, FIG. 2 illustrates that aheat treatment station 244 may be used to perform a heat treatment ofthe electrochromic stack. As an illustrative, non-limiting example,non-temperable stacks may be submitted to heat treatment at about 400°C. at the heat treatment station 244. As another illustrative,non-limiting example, to-be-tempered stacks may be submitted to heattreatment at about 700° C. at the heat treatment station 244.

FIG. 3 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 2 , according tosome embodiments.

FIG. 3 illustrates a particular embodiment in which an underlayer 302 ofthe electrochromic stack (formed at the underlayer station 202 of FIG. 2) may include multiple materials. For example, a first portion of theunderlayer 302 may correspond to a Nb₂O₅ layer having a first thickness(e.g., about 10 nm), and a second portion of the underlayer 302 maycorrespond to a SiO₂ layer having a second thickness (e.g., about 20nm).

FIG. 3 illustrates a particular embodiment in which a first conductivelayer 304 of the electrochromic stack (formed at the first conductivelayer station 204 of FIG. 2 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 3 illustrates a particular embodiment in which an electrochromicelectrode 310 of the electrochromic stack (formed at the electrodestation 210 of FIG. 2 ) may correspond to a WO_(x) EC layer having athickness of about 400 nm.

FIG. 3 illustrates a particular embodiment in which an IC 320 of theelectrochromic stack (formed at the IC station 220 of FIG. 2 ) maycorrespond to a SiO_(x) layer having a thickness of less than 5 nm. Inthe examples described herein, the presence of a silicon oxide IC layeris optional.

In FIG. 3 , a counter-electrode of the electrochromic stack includes afirst counter-electrode portion 330 and a second counter-electrodeportion 336, where metallic lithium 333 (formed at the single metalliclithium station 233 of FIG. 2 ) is “within” the counter-electrodebetween the first counter-electrode portion 330 and the secondcounter-electrode portion 336. FIG. 3 illustrates a particularembodiment in which the first counter-electrode portion 330 correspondsto a first NiWO_(x) layer (formed at the first counter-electrode station230 of FIG. 2 ) with a first thickness (identified as “X” nm in FIG. 3 )“below” the metallic lithium 333 in the stack. The secondcounter-electrode portion 336 corresponds to a second NiWO_(x) layer(formed at the second counter-electrode station 236 of FIG. 2 ) with asecond thickness (identified as “270-X” nm in FIG. 3 ) “above” themetallic lithium 333 in the stack. As previously described herein withrespect to FIG. 2 , tuning the first thickness of the firstcounter-electrode portion 330 “below” the metallic lithium 333 in theelectrochromic stack versus the second thickness of the secondcounter-electrode portion 336 “above” the metallic lithium 333 in theelectrochromic stack allows for tuning the amount of metallic lithiumthat diffuses to the WO_(x) electrode 310 during the firing process andallows for adapting the stack to different firing conditions. In aparticular embodiment, the first thickness (X) of the firstcounter-electrode portion 330 may be at least 20 nm and at most 250 nmfor a total counter-electrode thickness of about 270 nm.

FIG. 3 illustrates a particular embodiment in which a second conductivelayer 340 of the electrochromic stack (formed at the second conductivelayer station 240 of FIG. 2 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 3 illustrates a particular embodiment in which an overlayer 342 ofthe electrochromic stack (formed at the overlayer station 242 of FIG. 2) may correspond to a SiO_(x) layer having a thickness of about 70 nm.

Thus, FIGS. 2 and 3 illustrate a first embodiment of the presentdisclosure in which a single metallic lithium station is utilized todeposit metallic lithium within a counter-electrode layer of theelectrochromic stack. Tuning the thickness of a first portion of thecounter-electrode “below” the metallic lithium in the electrochromicstack versus the thickness of the second portion of thecounter-electrode “above” the metallic lithium in the electrochromicstack allows for tuning the amount of lithium that diffuses to theWO_(x) electrode during the firing process and allows for adapting thestack to different firing conditions.

FIG. 4 is a flow diagram depicting an example of a process of forming anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium onto an electrochromic electrodelayer and utilizing a lithium-containing ceramic target to form acounter-electrode layer of the electrochromic stack, according to someembodiments.

In FIG. 4 , a ceramic target containing lithium is used to sputter thecounter-electrode. Such a ceramic material is significantly easier tohandle than metallic lithium and can be processed in a standard,water-cooled magnetron compartment. In this configuration, metalliclithium is still sputtered to compensate for the blind charges of theelectrode and to introduce mobile lithium into the stack. The metalliclithium can, however, be sputtered in a single station. Tuning thecomposition of the lithium-containing ceramic counter-electrode allowsfor managing excess lithium that the counter-electrode needs compared tothe electrode before the firing step.

FIG. 4 illustrates a sequence of stations that may be used to form anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium onto an EC layer and utilizing alithium-containing ceramic target to form a CE layer of theelectrochromic stack.

An underlayer station 402 may be used to form an underlayer of anelectrochromic stack. In some embodiments, the underlayer station 402may be used to an underlayer that includes multiple materials. Toillustrate, the underlayer station 402 may be used to form one portionof the underlayer from one material and another portion of theunderlayer from a different material. As an illustrative, non-limitingexample, the first portion of the underlayer formed at the underlayerstation 402 may correspond to a first layer of a first material (e.g.,Nb₂O₅) with a first thickness according to an electrochromic stackdesign. The second portion of the underlayer formed at the underlayerstation 402 may correspond to a second layer of a second material (e.g.,SiO₂) with a second thickness according to the electrochromic stackdesign.

Proceeding from the underlayer station 402, FIG. 4 illustrates that afirst conductive layer station 404 may be used to form a firstconductive layer of the electrochromic stack. In a particularembodiment, the first conductive layer station 404 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the first conductive layer station 404, FIG. 4illustrates that an electrode station 410 may be used to form an EClayer of the electrochromic stack. In the particular embodiment depictedin FIG. 4 , the electrode station 410 utilizes a tungsten (W) target 412to form a WO_(x) EC layer with a particular thickness according to theelectrochromic stack design.

Proceeding from the electrode station 410, FIG. 4 illustrates that asingle metallic lithium station 413 may be used to deposit a layer ofmetallic lithium onto the WO_(x) EC layer. A thickness of the layer ofmetallic lithium may be determined based on various factors, includingthe particular electrochromic stack design and the particular firingconditions such that a satisfactory amount of the metallic lithiumdiffuses to the WO_(x) EC layer during the firing process.

Proceeding from the metallic lithium station 413, FIG. 4 illustratesthat, in some embodiments, an IC station 420 may be used to form an IClayer of the electrochromic stack. In a particular embodiment, the ICstation 420 may be used to form SiO_(x) layer with a particularthickness according to the electrochromic stack design. In alternativeembodiments, as indicated by the dashed lines in FIG. 4 , the IC station420 may be omitted.

Proceeding from the IC station 420 (or from the electrode station 410 incases where the IC station 420 is omitted), FIG. 4 illustrates that acounter-electrode station 430 may be used to form a CE layer of theelectrochromic stack. In the example depicted in FIG. 4 , thecounter-electrode station 430 utilizes a mixed lithium-nickel-tungsten(Li:Ni:W) ceramic target 432 to form a LiNiWO_(x) CE layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the counter-electrode station 430, FIG. 4 illustratesthat a second conductive layer station 440 may be used to form a secondconductive layer of the electrochromic stack. In a particularembodiment, the second conductive layer station 440 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the second conductive layer station 440, FIG. 4illustrates that an overlayer station 442 may be used to form anoverlayer of the electrochromic stack. In a particular embodiment, theoverlayer station 442 may be used to form a SiO_(x) layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the overlayer station 442, FIG. 4 illustrates that aheat treatment station 444 may be used to perform a heat treatment ofthe electrochromic stack.

FIG. 5 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 4 , according tosome embodiments.

FIG. 5 illustrates a particular embodiment in which an underlayer 502 ofthe electrochromic stack (formed at the underlayer station 402 of FIG. 4) may include multiple materials. For example, a first portion of theunderlayer 502 may correspond to a Nb₂O₅ layer having a first thickness(e.g., about 10 nm), and a second portion of the underlayer 502 maycorrespond to a SiO₂ layer having a second thickness (e.g., about 20nm).

FIG. 5 illustrates a particular embodiment in which a first conductivelayer 504 of the electrochromic stack (formed at the first conductivelayer station 404 of FIG. 4 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 5 illustrates a particular embodiment in which an electrochromicelectrode 510 of the electrochromic stack (formed at the electrodestation 410 of FIG. 4 ) may correspond to a WO_(x) EC layer having athickness of about 400 nm.

FIG. 5 illustrates a particular embodiment in which metallic lithium 513(formed at the single metallic lithium station 413 of FIG. 4 ) is“above” the EC layer 510 in the electrochromic stack. FIG. 5 illustratesa particular embodiment in which an IC 520 of the electrochromic stack(formed at the IC station 420 of FIG. 4 ) may correspond to a SiO_(x)layer having a thickness of less than 5 nm. FIG. 5 illustrates aparticular embodiment in which a counter-electrode 530 of theelectrochromic stack may correspond to a LiNiWO_(x) layer (formed at thecounter-electrode station 430 of FIG. 4 using the mixed Li:Ni:W ceramictarget 432) having a thickness of about 420 nm.

In the examples described herein, the presence of a silicon oxide IClayer is optional. Thus, while the embodiment depicted in FIG. 5 showsthe metallic lithium 513 positioned between the electrode 510 and the IC520, alternative embodiments may include the metallic lithium 513positioned directly between the electrode 510 and the counter-electrode530 (with no intervening IC 520).

FIG. 5 illustrates a particular embodiment in which a second conductivelayer 540 of the electrochromic stack (formed at the second conductivelayer station 440 of FIG. 4 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 5 illustrates a particular embodiment in which an overlayer 542 ofthe electrochromic stack (formed at the overlayer station 442 of FIG. 4) may correspond to a SiO_(x) layer having a thickness of about 70 nm.

Thus, FIGS. 4 and 5 illustrate a second embodiment of the presentdisclosure in which a single metallic lithium station is utilized todeposit metallic lithium above an electrode layer of the electrochromicstack, and a lithium-containing ceramic counter-electrode target isutilized to form a counter-electrode layer of the electrochromic stack.

FIG. 6 is a flow diagram depicting an example of a process of forming anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium within an electrochromic electrodelayer and utilizing a lithium-containing ceramic target to form acounter-electrode layer of the electrochromic stack, according to someembodiments.

In FIG. 6 , a ceramic target containing lithium is used to sputter thecounter-electrode. Such a ceramic material is significantly easier tohandle than metallic lithium and can be processed in a standard,water-cooled magnetron compartment. In this configuration, metalliclithium is still sputtered to compensate for the blind charges of theelectrode and to introduce mobile lithium into the stack. The metalliclithium can, however, be sputtered in a single station. Tuning thecomposition of the lithium-containing ceramic counter-electrode allowsfor managing excess lithium that the counter-electrode needs compared tothe electrode before the firing step.

FIG. 6 illustrates a sequence of stations that may be used to form anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium “within” an EC layer and utilizing alithium-containing ceramic target to form a CE layer of theelectrochromic stack.

An underlayer station 602 may be used to form an underlayer of anelectrochromic stack. In some embodiments, the underlayer station 602may be used to an underlayer that includes multiple materials. Toillustrate, the underlayer station 602 may be used to form one portionof the underlayer from one material and another portion of theunderlayer from a different material. As an illustrative, non-limitingexample, the first portion of the underlayer formed at the underlayerstation 602 may correspond to a first layer of a first material (e.g.,Nb₂O₅) with a first thickness according to an electrochromic stackdesign. The second portion of the underlayer formed at the underlayerstation 602 may correspond to a second layer of a second material (e.g.,SiO₂) with a second thickness according to the electrochromic stackdesign.

Proceeding from the underlayer station 602, FIG. 6 illustrates that afirst conductive layer station 604 may be used to form a firstconductive layer of the electrochromic stack. In a particularembodiment, the first conductive layer station 604 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the first conductive layer station 604, FIG. 6illustrates that a first electrode station 610 may be used to form afirst portion of an EC layer of the electrochromic stack. In the exampledepicted in FIG. 6 , the first electrode station 610 utilizes a tungsten(W) target 612 to form a first portion of a WO_(x) EC layer with a firstthickness. As described further herein, the first thickness may bedetermined based on various factors, including the particularelectrochromic stack design and the particular firing conditions.

Proceeding from the first electrode station 610, FIG. 6 illustrates thata single metallic lithium station 613 may be used to deposit a layer ofmetallic lithium onto the first portion of the WO_(x) EC layer. Athickness of the layer of metallic lithium may be determined based onvarious factors, including the particular electrochromic stack designand the particular firing conditions.

Proceeding from the metallic lithium station 613, FIG. 6 illustratesthat a second electrode station 614 may be used to form a second portionof the EC layer of the electrochromic stack. In the example depicted inFIG. 6 , the second electrode station 614 utilizes a tungsten (W) target616 to form the second portion of the WO_(x) EC layer with a secondthickness. As described further herein, the second thickness may bedetermined based on various factors, including the particularelectrochromic stack design and the particular firing conditions.

Tuning the thickness of the first portion of the EC layer (formed at thefirst electrode station 610) that is “below” the metallic lithium(formed at the metallic lithium station 613) in the electrochromic stackversus the thickness of the second portion of the EC layer (formed atthe second electrode station 614) that is “above” the metallic lithiumin the electrochromic stack allows for adapting the stack to differentfiring conditions. To illustrate, non-temperable stacks may be submittedto heat treatment at about 400° C. By contrast, to-be-tempered stacksmay be submitted to heat treatment at about 700° C. The position of themetallic lithium in the EC layer can be adjusted accordingly by varyingthe deposition power used in each of the electrode stations 610 and 614,according to some embodiments.

Proceeding from the second electrode station 614, FIG. 6 illustratesthat, in some embodiments, an IC station 620 may be used to form an IClayer of the electrochromic stack. In a particular embodiment, the ICstation 620 may be used to form SiO_(x) layer with a particularthickness according to the electrochromic stack design. In alternativeembodiments, as indicated by the dashed lines in FIG. 6 , the IC station620 may be omitted.

Proceeding from the IC station 620 (or from the second electrode station614 in cases where the IC station 620 is omitted), FIG. 6 illustratesthat a counter-electrode station 630 may be used to form a CE layer ofthe electrochromic stack. In the example depicted in FIG. 6 , thecounter-electrode station 630 utilizes a mixed lithium-nickel-tungsten(Li:Ni:W) ceramic target 632 to form a LiNiWO_(x) CE layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the counter-electrode station 630, FIG. 6 illustratesthat a second conductive layer station 640 may be used to form a secondconductive layer of the electrochromic stack. In a particularembodiment, the second conductive layer station 640 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the second conductive layer station 640, FIG. 6illustrates that an overlayer station 642 may be used to form anoverlayer of the electrochromic stack. In a particular embodiment, theoverlayer station 642 may be used to form a SiO_(x) layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the overlayer station 642, FIG. 6 illustrates that aheat treatment station 644 may be used to perform a heat treatment ofthe electrochromic stack.

FIG. 7 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 6 , according tosome embodiments.

FIG. 7 illustrates a particular embodiment in which an underlayer 702 ofthe electrochromic stack (formed at the underlayer station 602 of FIG. 6) may include multiple materials. For example, a first portion of theunderlayer 702 may correspond to a Nb₂O₅ layer having a first thickness(e.g., about 10 nm), and a second portion of the underlayer 702 maycorrespond to a SiO₂ layer having a second thickness (e.g., about 20nm).

FIG. 7 illustrates a particular embodiment in which a first conductivelayer 704 of the electrochromic stack (formed at the first conductivelayer station 604 of FIG. 6 ) may correspond to an ITO layer having athickness of about 420 nm.

In FIG. 7 , an electrode of the electrochromic stack includes a firstelectrode portion 710 and a second electrode portion 714, where metalliclithium 713 (formed at the single metallic lithium station 613 of FIG. 6) is “within” the electrode between the first electrode portion 710 andthe second electrode portion 714. FIG. 7 illustrates a particularembodiment in which the first electrode portion 710 corresponds to afirst WO_(x) layer (formed at the first electrode station 610 of FIG. 6) with a first thickness (identified as “X” nm in FIG. 7 ) “below” themetallic lithium 713 in the stack. The second electrode portion 714corresponds to a second WO_(x) layer (formed at the second electrodestation 614 of FIG. 6 ) with a second thickness (identified as “400-X”nm in FIG. 7 ) “above” the metallic lithium 713 in the stack. Aspreviously described herein with respect to FIG. 6 , tuning the firstthickness of the first electrode portion 710 “below” the metalliclithium 713 in the electrochromic stack versus the second thickness ofthe second electrode portion 714 “above” the metallic lithium 713 in theelectrochromic stack allows for adapting the stack to different firingconditions. In a particular embodiment, the first thickness (X) of thefirst electrode portion 710 may be at least 20 nm and at most 380 nm fora total electrode thickness of about 400 nm.

FIG. 7 illustrates a particular embodiment in which an IC 720 of theelectrochromic stack (formed at the IC station 620 of FIG. 6 ) maycorrespond to a SiO_(x) layer having a thickness of less than 5 nm. Inthe examples described herein, the presence of a silicon oxide IC layeris optional.

FIG. 7 illustrates a particular embodiment in which a counter-electrode730 of the electrochromic stack may correspond to a LiNiWO_(x) layer(formed at the counter-electrode station 630 of FIG. 6 using the mixedLi:Ni:W ceramic target 632) having a thickness of about 270 nm.

FIG. 7 illustrates a particular embodiment in which a second conductivelayer 740 of the electrochromic stack (formed at the second conductivelayer station 640 of FIG. 6 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 7 illustrates a particular embodiment in which an overlayer 742 ofthe electrochromic stack (formed at the overlayer station 642 of FIG. 6) may correspond to a SiO_(x) layer having a thickness of about 70 nm.

Thus, FIGS. 6 and 7 illustrate a third embodiment of the presentdisclosure in which a single metallic lithium station is utilized todeposit metallic lithium “within” an electrode layer of theelectrochromic stack, and a lithium-containing ceramic counter-electrodetarget (e.g., LiNiWO_(x)) is utilized to form a counter-electrode layerof the electrochromic stack.

FIG. 8 is a flow diagram depicting an example of a process of forming anelectrochromic stack by utilizing lithium-containing ceramic targets toform an electrochromic electrode layer and a counter-electrode layer ofthe electrochromic stack, according to some embodiments. Such ceramicmaterials are significantly easier to handle than metallic lithium andcan be processed in a standard, water-cooled magnetron compartment.Utilizing lithium-containing ceramic targets to sputter both theelectrode and the counter-electrode can potentially allow for completelyremoving any metallic lithium deposition process, provided that Li is insufficient quantity in the electrode and counter-electrode, withcomposition Li_(x)Ni_(y)W_(z)O_(A) with X>(Y+Z)/2. In a particularembodiment, the composition of Li_(x)Ni_(y)W_(z)O_(A) is(Y+Z/2)<X<(2y+Z).

FIG. 8 illustrates a sequence of stations that may be used to form anelectrochromic stack that includes utilizing no metallic lithium stationand utilizing lithium-containing ceramic targets to form an EC layer anda CE layer of the electrochromic stack.

An underlayer station 802 may be used to form an underlayer of anelectrochromic stack. In some embodiments, the underlayer station 802may be used to an underlayer that includes multiple materials. Toillustrate, the underlayer station 802 may be used to form one portionof the underlayer from one material and another portion of theunderlayer from a different material. As an illustrative, non-limitingexample, the first portion of the underlayer formed at the underlayerstation 802 may correspond to a first layer of a first material (e.g.,Nb₂O₅) with a first thickness according to an electrochromic stackdesign. The second portion of the underlayer formed at the underlayerstation 802 may correspond to a second layer of a second material (e.g.,SiO₂) with a second thickness according to the electrochromic stackdesign.

Proceeding from the underlayer station 802, FIG. 8 illustrates that afirst conductive layer station 804 may be used to form a firstconductive layer of the electrochromic stack. In a particularembodiment, the first conductive layer station 804 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the first conductive layer station 804, FIG. 8illustrates that an electrode station 810 may be used to form an EClayer of the electrochromic stack. In the example depicted in FIG. 8 ,the electrode station 810 utilizes a mixed lithium-tungsten (Li:W)ceramic target 812 to form a LiWO_(x) EC layer with a particularthickness according to the electrochromic stack design.

Proceeding from the electrode station 810, FIG. 8 illustrates that, insome embodiments, an IC station 820 may be used to form an IC layer ofthe electrochromic stack. In a particular embodiment, the IC station 820may be used to form SiO_(x) layer with a particular thickness accordingto the electrochromic stack design. In alternative embodiments, asindicated by the dashed lines in FIG. 8 , the IC station 820 may beomitted.

Proceeding from the IC station 820 (or from the electrode station 810 incases where the IC station 820 is omitted), FIG. 8 illustrates that acounter-electrode station 830 may be used to form a CE layer of theelectrochromic stack. In the example depicted in FIG. 8 , thecounter-electrode station 830 utilizes a mixed lithium-nickel-tungsten(Li:Ni:W) ceramic target 832 to form a LiNiWO_(x) CE layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the counter-electrode station 830, FIG. 8 illustratesthat a second conductive layer station 840 may be used to form a secondconductive layer of the electrochromic stack. In a particularembodiment, the second conductive layer station 840 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the second conductive layer station 840, FIG. 8illustrates that an overlayer station 842 may be used to form anoverlayer of the electrochromic stack. In a particular embodiment, theoverlayer station 842 may be used to form a SiO_(x) layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the overlayer station 842, FIG. 8 illustrates that aheat treatment station 844 may be used to perform a heat treatment ofthe electrochromic stack.

FIG. 9 is a block diagram depicting various layers of the electrochromicstack formed according to the process depicted in FIG. 8 , according tosome embodiments.

FIG. 9 illustrates a particular embodiment in which an underlayer 902 ofthe electrochromic stack (formed at the underlayer station 802 of FIG. 8) may include multiple materials. For example, a first portion of theunderlayer 902 may correspond to a Nb₂O₅ layer having a first thickness(e.g., about 10 nm), and a second portion of the underlayer 902 maycorrespond to a SiO₂ layer having a second thickness (e.g., about 20nm).

FIG. 9 illustrates a particular embodiment in which a first conductivelayer 904 of the electrochromic stack (formed at the first conductivelayer station 804 of FIG. 8 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 9 illustrates a particular embodiment in which an electrode 910 ofthe electrochromic stack may correspond to a LiWO_(x) layer (formed atthe electrode station 810 of FIG. 8 using the mixed Li:W ceramic target812) having a thickness of about 400 nm.

FIG. 9 illustrates a particular embodiment in which an IC 920 of theelectrochromic stack (formed at the IC station 820 of FIG. 8 ) maycorrespond to a SiO_(x) layer having a thickness of less than 5 nm. Inthe examples described herein, the presence of a silicon oxide IC layeris optional.

FIG. 9 illustrates a particular embodiment in which a counter-electrode930 of the electrochromic stack may correspond to a LiNiWO_(x) layer(formed at the counter-electrode station 830 of FIG. 8 using the mixedLi:Ni:W ceramic target 832) having a thickness of about 270 nm.

FIG. 9 illustrates a particular embodiment in which a second conductivelayer 940 of the electrochromic stack (formed at the second conductivelayer station 840 of FIG. 8 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 9 illustrates a particular embodiment in which an overlayer 942 ofthe electrochromic stack (formed at the overlayer station 842 of FIG. 8) may correspond to a SiO_(x) layer having a thickness of about 70 nm.

Thus, FIGS. 8 and 9 illustrate a fourth embodiment of the presentdisclosure in which lithium-containing ceramic targets are utilized toform both an electrochromic electrode layer and an electrochromiccounter-electrode layer of the electrochromic stack. Utilizinglithium-containing ceramic targets to sputter both the electrode and thecounter-electrode can potentially allow for completely removing anymetallic lithium deposition process, provided that Li is in sufficientquantity in the electrode and counter-electrode.

FIG. 10 is a flow diagram depicting an example of a process of formingan electrochromic stack that includes utilizing a lithium-containingceramic target to form an electrochromic electrode layer of theelectrochromic stack and utilizing a single metallic lithium station todeposit metallic lithium onto a counter-electrode layer of theelectrochromic stack, according to some embodiments.

In FIG. 10 , a ceramic target containing lithium is used to sputter theelectrode. Such a ceramic material is significantly easier to handlethan metallic lithium and can be processed in a standard, water-cooledmagnetron compartment. FIG. 10 illustrates that, in some cases, a smallamount of metallic lithium (corresponding to a maximum quantity of Liions of 35 mC/cm²) can optionally be sputtered to add mobile lithium tothe stack. Because the amount of sputtered metallic lithium is reduced,this configuration may potentially allow for maintaining a highmanufacturing speed (e.g., greater than 0.5 meters/minute) with only onepair of targets available to sputter metallic lithium. In the embodimentdepicted in FIG. 10 , metallic lithium is sputtered above thecounter-electrode due to the positive impact of excess lithium on theelectrochromic properties of that material after thermal treatment.

FIG. 10 illustrates a sequence of stations that may be used to form anelectrochromic stack that includes utilizing a lithium-containingceramic target to form an EC layer of the electrochromic stack utilizinga single metallic lithium station to deposit metallic lithium over a CElayer of the electrochromic stack.

An underlayer station 1002 may be used to form an underlayer of anelectrochromic stack. In some embodiments, the underlayer station 1002may be used to an underlayer that includes multiple materials. Toillustrate, the underlayer station 1002 may be used to form one portionof the underlayer from one material and another portion of theunderlayer from a different material. As an illustrative, non-limitingexample, the first portion of the underlayer formed at the underlayerstation 1002 may correspond to a first layer of a first material (e.g.,Nb₂O₅) with a first thickness according to an electrochromic stackdesign. The second portion of the underlayer formed at the underlayerstation 1002 may correspond to a second layer of a second material(e.g., SiO₂) with a second thickness according to the electrochromicstack design.

Proceeding from the underlayer station 1002, FIG. 10 illustrates that afirst conductive layer station 1004 may be used to form a firstconductive layer of the electrochromic stack. In a particularembodiment, the first conductive layer station 1004 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the first conductive layer station 1004, FIG. 10illustrates that an electrode station 1010 may be used to form an EClayer of the electrochromic stack. In the example depicted in FIG. 10 ,the electrode station 1010 utilizes a mixed lithium-tungsten (Li:W)ceramic target 1012 to form a LiWO_(x) EC layer with a particularthickness according to the electrochromic stack design.

Proceeding from the electrode station 1010, FIG. 10 illustrates that, insome embodiments, an IC station 1020 may be used to form an IC layer ofthe electrochromic stack. In a particular embodiment, the IC station1020 may be used to form SiO_(x) layer with a particular thicknessaccording to the electrochromic stack design. In alternativeembodiments, as indicated by the dashed lines in FIG. 10 , the ICstation 1020 may be omitted.

Proceeding from the IC station 1020 (or from the electrode station 1010in cases where the IC station 1020 is omitted), FIG. 10 illustrates thata counter-electrode station 1030 may be used to form a CE layer of theelectrochromic stack. In the example depicted in FIG. 10 , thecounter-electrode station 1030 utilizes a mixed nickel-tungsten (Ni:W)target 832 to form a NiWO_(x) CE layer with a particular thicknessaccording to the electrochromic stack design.

Proceeding from the counter-electrode station 1030, FIG. 10 illustratesthat a single metallic lithium station 1033 may be used to deposit alayer of metallic lithium onto the NiWO_(x) CE layer. A thickness of thelayer of metallic lithium may be determined based on various factors,including the particular electrochromic stack design and the particularfiring conditions.

Proceeding from the single metallic lithium station 1033, FIG. 10illustrates that a second conductive layer station 1040 may be used toform a second conductive layer of the electrochromic stack. In aparticular embodiment, the second conductive layer station 1040 may beused to form an ITO layer with a particular thickness according to theelectrochromic stack design.

Proceeding from the second conductive layer station 1040, FIG. 10illustrates that an overlayer station 1042 may be used to form anoverlayer of the electrochromic stack. In a particular embodiment, theoverlayer station 1042 may be used to form a SiO_(x) layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the overlayer station 1042, FIG. 10 illustrates that aheat treatment station 1044 may be used to perform a heat treatment ofthe electrochromic stack.

FIG. 11 is a block diagram depicting various layers of theelectrochromic stack formed according to the process depicted in FIG. 10, according to some embodiments.

FIG. 11 illustrates a particular embodiment in which an underlayer 1102of the electrochromic stack (formed at the underlayer station 1002 ofFIG. 10 ) may include multiple materials. For example, a first portionof the underlayer 1102 may correspond to a Nb₂O₅ layer having a firstthickness (e.g., about 10 nm), and a second portion of the underlayer1102 may correspond to a SiO₂ layer having a second thickness (e.g.,about 20 nm).

FIG. 11 illustrates a particular embodiment in which a first conductivelayer 1104 of the electrochromic stack (formed at the first conductivelayer station 1004 of FIG. 10 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 11 illustrates a particular embodiment in which an electrode 1110of the electrochromic stack may correspond to a LiWO_(x) layer (formedat the electrode station 1010 of FIG. 10 using the mixed Li:W ceramictarget 1012) having a thickness of about 400 nm.

FIG. 11 illustrates a particular embodiment in which an IC 1120 of theelectrochromic stack (formed at the IC station 1020 of FIG. 10 ) maycorrespond to a SiO_(x) layer having a thickness of less than 5 nm. Inthe examples described herein, the presence of a silicon oxide IC layeris optional.

FIG. 11 illustrates a particular embodiment in which a counter-electrode1130 of the electrochromic stack may correspond to a NiWO_(x) layer(formed at the counter-electrode station 1030 of FIG. 10 using the mixedNi:W target 1032) having a thickness of about 270 nm.

FIG. 11 illustrates a particular embodiment in which metallic lithium1133 (formed at the single metallic lithium station 1033 of FIG. 10 ) is“above” the CE layer 1130 in the electrochromic stack.

FIG. 11 illustrates a particular embodiment in which a second conductivelayer 1140 of the electrochromic stack (formed at the second conductivelayer station 1040 of FIG. 10 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 11 illustrates a particular embodiment in which an overlayer 1142of the electrochromic stack (formed at the overlayer station 1042 ofFIG. 10 ) may correspond to a SiO_(x) layer having a thickness of about70 nm.

Thus, FIGS. 10 and 11 illustrate a fifth embodiment of the presentdisclosure in which a lithium-containing ceramic electrode target isutilized to form an electrode layer of the electrochromic stack, and asingle metallic lithium station is utilized to deposit metallic lithiumabove a counter-electrode layer of the electrochromic stack.

FIG. 12 is a flow diagram depicting an example of a process of formingan electrochromic stack that includes utilizing a single metalliclithium station to deposit metallic lithium between an IC layer and anelectrode layer of the electrochromic stack, according to someembodiments.

FIG. 12 illustrates a sequence of stations that may be used to form anelectrochromic stack that includes utilizing a single metallic lithiumstation to deposit metallic lithium between the IC layer and theelectrode layer of the electrochromic stack.

An underlayer station 1202 may be used to form an underlayer of anelectrochromic stack. In some embodiments, the underlayer station 1202may be used to an underlayer that includes multiple materials. Toillustrate, the underlayer station 1202 may be used to form one portionof the underlayer from one material and another portion of theunderlayer from a different material. As an illustrative, non-limitingexample, the first portion of the underlayer formed at the underlayerstation 1202 may correspond to a first layer of a first material (e.g.,Nb₂O₅) with a first thickness according to an electrochromic stackdesign. The second portion of the underlayer formed at the underlayerstation 1202 may correspond to a second layer of a second material(e.g., SiO₂) with a second thickness according to the electrochromicstack design.

Proceeding from the underlayer station 1202, FIG. 12 illustrates that afirst conductive layer station 1204 may be used to form a firstconductive layer of the electrochromic stack. In a particularembodiment, the first conductive layer station 1204 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the first conductive layer station 1204, FIG. 12illustrates that a counter-electrode station 1217 may be used to form aCE layer of the electrochromic stack. In the example depicted in FIG. 12, the counter-electrode station 1217 utilizes a mixed nickel-tungsten(Ni:W) target 1218 to form the CE layer with a particular thickness. Asdescribed further herein, the thickness of the CE layer may bedetermined based on various factors, including the particularelectrochromic stack design.

Proceeding from the counter-electrode station 1217, FIG. 12 illustratesthat an IC station 1220 may be used to form an IC layer of theelectrochromic stack. In a particular embodiment, the IC station 1220may be used to form SiO_(x) layer with a particular thickness accordingto the electrochromic stack design.

Proceeding from the IC station 1220, FIG. 12 illustrates that a singlemetallic lithium station 1221 may be used to deposit a layer of metalliclithium onto the IC layer. A thickness of the layer of metallic lithiummay be determined based on various factors, including the particularelectrochromic stack design and the particular firing conditions suchthat a satisfactory amount of the metallic lithium diffuses to a WO_(x)EC layer (formed at electrode station 1237) during the firing process.

Proceeding from the single metallic lithium station 1221, FIG. 12illustrates that an electrode station 1237 may be used to form an EClayer of the electrochromic stack. In the particular embodiment depictedin FIG. 12 , the electrode station 1237 utilizes a tungsten (W) target1238 to form a WO_(x) EC layer with a particular thickness according tothe electrochromic stack design.

Proceeding from the electrode station 1237, FIG. 12 illustrates that asecond conductive layer station 1240 may be used to form a secondconductive layer of the electrochromic stack. In a particularembodiment, the second conductive layer station 1240 may be used to forman ITO layer with a particular thickness according to the electrochromicstack design.

Proceeding from the second conductive layer station 1240, FIG. 12illustrates that an overlayer station 1242 may be used to form anoverlayer of the electrochromic stack. In a particular embodiment, theoverlayer station 1242 may be used to form a SiO_(x) layer with aparticular thickness according to the electrochromic stack design.

Proceeding from the overlayer station 1242, FIG. 12 illustrates that, insome embodiments, an optional heat treatment station 1244 may be used toperform a heat treatment of the electrochromic stack. As anillustrative, non-limiting example, non-temperable stacks may besubmitted to heat treatment at about 400° C. at the heat treatmentstation 1244, according to some embodiments.

FIG. 13 is a block diagram depicting various layers of theelectrochromic stack formed according to the process depicted in FIG. 12, according to some embodiments.

FIG. 13 illustrates a particular embodiment in which an underlayer 1302of the electrochromic stack (formed at the underlayer station 1202 ofFIG. 12 ) may include multiple materials. For example, a first portionof the underlayer 1302 may correspond to a Nb₂O₅ layer having a firstthickness (e.g., about 10 nm), and a second portion of the underlayer1302 may correspond to a SiO₂ layer having a second thickness (e.g.,about 30 nm).

FIG. 13 illustrates a particular embodiment in which a first conductivelayer 1304 of the electrochromic stack (formed at the first conductivelayer station 1204 of FIG. 12 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 13 illustrates a particular embodiment in which a CE layer 1317 ofthe electrochromic stack (formed at the CE layer station 1217 of FIG. 12) may correspond to a NiWO_(x) layer having a thickness of about 270 nm.

FIG. 13 illustrates a particular embodiment in which an IC 1320 of theelectrochromic stack (formed at the IC station 1220 of FIG. 12 ) maycorrespond to a SiO_(x) layer having a thickness of less than 5 nm.

In FIG. 13 , metallic lithium 1321 (formed at the single metalliclithium station 1221 of FIG. 12 ) is deposited “above” the IC layer 1320and “below” an electrode layer 1337 (formed at the EC layer station 1237of FIG. 12 ).

FIG. 13 illustrates a particular embodiment in which a second conductivelayer 1340 of the electrochromic stack (formed at the second conductivelayer station 1240 of FIG. 12 ) may correspond to an ITO layer having athickness of about 420 nm.

FIG. 13 illustrates a particular embodiment in which an overlayer 1342of the electrochromic stack (formed at the overlayer station 1242 ofFIG. 12 ) may correspond to a SiO_(x) layer having a thickness of about70 nm.

Thus, FIGS. 12 and 13 illustrate another embodiment of the presentdisclosure in which a CE layer and an IC layer are deposited before anEC layer, and a single metallic lithium station is utilized to depositmetallic lithium “above” the IC layer and “below” the EC layer in thestack.

In some embodiments of the present disclosure, an electrochromic stackmay be formed according to a process comprising: depositing, at anelectrode station, an electrochromic electrode (EC) layer of anelectrochromic stack; depositing, at a first counter-electrode station,a first portion of an electrochromic counter-electrode (CE) layer of theelectrochromic stack; depositing, at a single metallic lithium station,metallic lithium onto the first portion of the electrochromic CE layerdeposited at the first counter-electrode station; and depositing, at asecond counter-electrode station, a second portion of the electrochromicCE layer onto the metallic lithium deposited at the single metalliclithium station. In some cases, the process may further includeperforming a heat treatment of the electrochromic stack subsequent todepositing the second portion of the electrochromic CE layer.

In some embodiments of the present disclosure, an electrochromic stackmay be formed according to a process comprising: depositing, at anelectrode station, at least a portion of an electrochromic electrode(EC) layer of an electrochromic stack; depositing, at a single metalliclithium station, metallic lithium onto the electrochromic EC layerdeposited at the electrode station; and depositing, at acounter-electrode station, an electrochromic counter-electrode (CE)layer of the electrochromic stack utilizing a lithium-containing ceramiccounter-electrode target. In some cases, the process may further includeperforming a heat treatment of the electrochromic stack subsequent todepositing the electrochromic CE layer.

In some embodiments of the present disclosure, an electrochromic stackmay be formed according to a process comprising: depositing, at anelectrode station, an electrochromic electrode (EC) layer of theelectrochromic stack utilizing a lithium-containing ceramic electrodetarget; and depositing, at a counter-electrode station, anelectrochromic counter-electrode (CE) layer of the electrochromic stackutilizing a counter-electrode target. In some cases, the process mayfurther include performing a heat treatment of the electrochromic stacksubsequent to depositing the electrochromic CE layer.

Embodiments of the present disclosure can be described in view of thefollowing clauses:

-   -   Clause 1. A process of forming an electrochromic stack, the        process comprising:    -   depositing, at an electrode station, an electrochromic electrode        (EC) layer of an electrochromic stack;    -   depositing, at a first counter-electrode station, a first        portion of an electrochromic counter-electrode (CE) layer of the        electrochromic stack;    -   depositing, at a single metallic lithium station, metallic        lithium onto the first portion of the electrochromic CE layer        deposited at the first counter-electrode station; and    -   depositing, at a second counter-electrode station, a second        portion of the electrochromic CE layer onto the metallic lithium        deposited at the single metallic lithium station.    -   Clause 2. The process of clause 1, further comprising:    -   depositing, at an underlayer station, an underlayer of the        electrochromic stack; and    -   depositing, at a first conductive layer station, a first        conductive layer of the electrochromic stack,    -   wherein the electrochromic EC layer is deposited onto the first        conductive layer deposited at the first conductive layer        station.    -   Clause 3. The process of clause 2, further comprising:    -   depositing, at an ion-conducting (IC) station, an IC layer of        the electrochromic stack onto the electrochromic EC layer        deposited at the electrode station,    -   wherein the first portion of the electrochromic CE layer is        deposited onto the IC layer deposited at the IC station.    -   Clause 4. The process of clause 2, wherein the first portion of        the electrochromic CE layer is deposited onto the electrochromic        EC layer deposited at the electrode station.    -   Clause 5. The process of clause 2, further comprising:    -   depositing, at a second conductive layer station, a second        conductive layer of the electrochromic stack; and    -   depositing, at an overlayer station, an overlayer of the        electrochromic stack.    -   Clause 6. The process of clause 5, further comprising performing        a heat treatment of the electrochromic stack subsequent to        depositing the overlayer.    -   Clause 7. The process of clause 1, wherein the first portion of        the electrochromic CE layer has a first thickness that is not        less than 20 nm, and wherein the first portion of the        electrochromic CE layer and the second portion of the        electrochromic CE layer have a combined thickness of about 270        nm.    -   Clause 8. A process of forming an electrochromic stack, the        process comprising:    -   depositing, at an electrode station, an electrochromic electrode        (EC) layer of the electrochromic stack utilizing a        lithium-containing ceramic electrode target; and    -   depositing, at a counter-electrode station, an electrochromic        counter-electrode (CE) layer of the electrochromic stack        utilizing a counter-electrode target.    -   Clause 9. The process of clause 8, wherein the counter-electrode        target is a lithium-containing ceramic counter-electrode target.    -   Clause 10. The process of clause 9, wherein the        lithium-containing ceramic counter-electrode target includes a        mixed lithium-nickel-tungsten (Li:Ni:W) ceramic target.    -   Clause 11. The process of clause 8, wherein the        lithium-containing ceramic electrode target includes a mixed        lithium-tungsten (Li:W) ceramic target.    -   Clause 12. The process of clause 8, further comprising        depositing, at a single metallic lithium station, metallic        lithium.    -   Clause 13. The process of clause 12, wherein the metallic        lithium is deposited onto the electrochromic CE layer deposited        at the counter-electrode station.    -   Clause 14. The process of clause 13, wherein the ceramic        counter-electrode target includes a mixed nickel-tungsten (Ni:W)        target.    -   Clause 15. A process of forming an electrochromic stack, the        process comprising:    -   depositing, at a counter-electrode station, an electrochromic        counter-electrode (CE) layer of an electrochromic stack;    -   depositing, at an ion-conducting (IC) station, an IC layer of        the electrochromic stack;    -   depositing, at a single metallic lithium station, metallic        lithium onto the IC layer; and    -   depositing, at an electrochromic electrode (EC) station, an        electrochromic EC layer onto the metallic lithium deposited at        the single metallic lithium station.    -   Clause 16. The process of clause 15, further comprising:    -   depositing, at an underlayer station, an underlayer of the        electrochromic stack; and    -   depositing, at a first conductive layer station, a first        conductive layer of the electrochromic stack,    -   wherein the electrochromic CE layer is deposited onto the first        conductive layer deposited at the first conductive layer        station.    -   Clause 17. The process of clause 16, further comprising:    -   depositing, at a second conductive layer station, a second        conductive layer of the electrochromic stack onto the        electrochromic EC layer; and    -   depositing, at an overlayer station, an overlayer of the        electrochromic stack onto the second conductive layer.    -   Clause 18. The process of clause 17, further comprising        performing a heat treatment of the electrochromic stack        subsequent to depositing the overlayer.    -   Clause 19. An electrochromic stack having a single layer of        metallic lithium disposed within the electrochromic stack, the        electrochromic stack comprising: an electrochromic electrode        (EC) layer;    -   an electrochromic counter-electrode (CE) layer overlying the        electrochromic EC layer, the electrochromic CE layer comprising:        -   a first portion overlying the electrochromic EC layer;        -   metallic lithium directly overlying the first portion of the            electrochromic CE layer; and        -   a second portion directly overlying the metallic lithium.    -   Clause 20. The electrochromic stack of clause 19, further        comprising an ion-conducting (IC) layer disposed between the        electrochromic EC layer and the first portion of the        electrochromic CE layer.    -   Clause 21. The electrochromic stack of clause 19, wherein the        first portion of the electrochromic CE layer has a first        thickness that is not less than 20 nm, and wherein the first        portion of the electrochromic CE layer and the second portion of        the electrochromic CE layer have a combined thickness of about        270 nm.    -   Clause 22. An electrochromic device, comprising:    -   an electrochromic stack having a single layer of metallic        lithium disposed within the electrochromic stack, the        electrochromic stack comprising:        -   an electrochromic electrode (EC) layer;        -   an electrochromic counter-electrode (CE) layer overlying the            electrochromic EC layer, the electrochromic CE layer            comprising:            -   a first portion overlying the electrochromic EC layer;            -   metallic lithium directly overlying the first portion of                the electrochromic CE layer; and            -   a second portion directly overlying the metallic                lithium.    -   Clause 23. The electrochromic device of clause 22, further        comprising an ion-conducting (IC) layer disposed between the        electrochromic EC layer and the first portion of the        electrochromic CE layer.    -   Clause 24. The electrochromic device of clause 22, wherein the        first portion of the electrochromic CE layer has a first        thickness that is not less than 20 nm, and wherein the first        portion of the electrochromic CE layer and the second portion of        the electrochromic CE layer have a combined thickness of about        270 nm.    -   Clause 25. An electrochromic stack having no metallic lithium        disposed within the electrochromic stack, the electrochromic        stack comprising:    -   an electrochromic electrode (EC) layer comprising a LiWO_(x)        material; and    -   an electrochromic counter-electrode (CE) layer overlying the        electrochromic EC layer, the electrochromic CE layer comprising        a LiNiWO_(x) material.    -   Clause 26. The electrochromic stack of clause 25, further        comprising an ion-conducting (IC) layer disposed between the        electrochromic EC layer and the electrochromic CE layer.    -   Clause 27. An electrochromic device, comprising:    -   an electrochromic stack having no metallic lithium disposed        within the electrochromic stack, the electrochromic stack        comprising:        -   an electrochromic electrode (EC) layer comprising a LiWO_(x)            material; and        -   an electrochromic counter-electrode (CE) layer overlying the            electrochromic EC layer, the electrochromic CE layer            comprising a LiNiWO_(x) material.    -   Clause 28. The electrochromic device of clause 27, further        comprising an ion-conducting (IC) layer disposed between the        electrochromic EC layer and the electrochromic CE layer.    -   Clause 29. An electrochromic stack having a single layer of        metallic lithium disposed within the electrochromic stack, the        electrochromic stack comprising: an electrochromic electrode        (EC) layer, the electrochromic EC layer comprising a        -   LiWO_(x) material;    -   an electrochromic counter-electrode (CE) layer overlying the        electrochromic EC layer; and    -   metallic lithium directly overlying the electrochromic CE layer.    -   Clause 30. The electrochromic stack of clause 29, further        comprising an ion-conducting (IC) layer disposed between the        electrochromic EC layer and the electrochromic CE layer.    -   Clause 31. An electrochromic device, comprising:    -   an electrochromic stack having a single layer of metallic        lithium disposed within the electrochromic stack, the        electrochromic stack comprising:        -   an electrochromic electrode (EC) layer, the electrochromic            EC layer comprising a LiWO_(x) material;        -   an electrochromic counter-electrode (CE) layer overlying the            electrochromic EC layer; and        -   metallic lithium directly overlying the electrochromic CE            layer.    -   Clause 32. The electrochromic device of clause 31, further        comprising an ion-conducting (IC) layer disposed between the        electrochromic EC layer and the electrochromic CE layer.    -   Clause 33. An electrochromic stack having a single layer of        metallic lithium disposed within the electrochromic stack, the        electrochromic stack comprising:    -   an electrochromic counter-electrode (CE) layer;    -   an ion-conducting (IC) layer directly overlying the        electrochromic CE layer;    -   metallic lithium directly overlying the IC layer; and    -   an electrochromic electrode (EC) layer directly overlying the        metallic lithium.    -   Clause 34. The electrochromic stack of clause 33, further        comprising an underlayer, wherein the electrochromic CE layer        overlies the underlayer.    -   Clause 35. The electrochromic stack of clause 33, further        comprising an overlayer overlying the electrochromic EC layer.    -   Clause 36. An electrochromic device, comprising:    -   an electrochromic stack having a single layer of metallic        lithium disposed within the electrochromic stack, the        electrochromic stack comprising:        -   an electrochromic counter-electrode (CE) layer;        -   an ion-conducting (IC) layer directly overlying the            electrochromic CE layer;        -   metallic lithium directly overlying the IC layer; and        -   an electrochromic electrode (EC) layer directly overlying            the metallic lithium.    -   Clause 37. The electrochromic device of clause 36, further        comprising:    -   an underlayer, wherein the electrochromic CE layer overlies the        underlayer; and    -   an overlayer overlying the electrochromic EC layer.    -   Clause 38. An electrochromic stack formed according to a process        comprising:    -   depositing, at an electrode station, an electrochromic electrode        (EC) layer of an electrochromic stack;    -   depositing, at a first counter-electrode station, a first        portion of an electrochromic counter-electrode (CE) layer of the        electrochromic stack;    -   depositing, at a single metallic lithium station, metallic        lithium onto the first portion of the electrochromic CE layer        deposited at the first counter-electrode station; and    -   depositing, at a second counter-electrode station, a second        portion of the electrochromic CE layer onto the metallic lithium        deposited at the single metallic lithium station.    -   Clause 39. The electrochromic stack of clause 38, the process        further comprising performing a heat treatment of the        electrochromic stack subsequent to depositing the second portion        of the electrochromic CE layer.    -   Clause 40. An electrochromic stack formed according to a process        comprising:    -   depositing, at an electrode station, an electrochromic electrode        (EC) layer of the electrochromic stack utilizing a        lithium-containing ceramic electrode target; and    -   depositing, at a counter-electrode station, an electrochromic        counter-electrode (CE) layer of the electrochromic stack        utilizing a counter-electrode target.    -   Clause 41. The electrochromic stack of clause 40, the process        further comprising performing a heat treatment of the        electrochromic stack subsequent to depositing the electrochromic        CE layer.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications may be made as wouldbecome apparent to those skilled in the art once the above disclosure isfully appreciated. It is intended that the following claims beinterpreted to embrace all such modifications and changes and,accordingly, the above description to be regarded in an illustrativerather than a restrictive sense.

1.-20. (canceled)
 21. An electrochromic stack having a single layer ofmetallic lithium disposed within the electrochromic stack, theelectrochromic stack comprising: an electrochromic electrode (EC) layerformed from depositing the EC layer utilizing a lithium-containingceramic electrode target; an electrochromic counter-electrode (CE) layeroverlying the electrochromic EC layer; and a metallic lithium layerdeposited over at least a portion of the electrochromic CE layer,wherein the metallic lithium layer is the only layer of theelectrochromic stack deposited with metallic lithium.
 22. Theelectrochromic stack of claim 21, further comprising an ion-conducting(IC) layer disposed between the electrochromic EC layer and theelectrochromic CE layer.
 23. The electrochromic stack of claim 21,wherein: the electrochromic CE layer includes a first portion and asecond portion; the metallic lithium layer is deposited directly overthe first portion of the electrochromic CE layer; and the second portionof the electrochromic CE layer is formed directly over the metalliclithium layer.
 24. The electrochromic stack of claim 23, furthercomprising an ion-conducting (IC) layer disposed between theelectrochromic EC layer and the first portion of the electrochromic CElayer.
 25. The electrochromic stack of claim 23, wherein the firstportion of the electrochromic CE layer has a first thickness that is notless than 20 nm, and wherein the first portion of the electrochromic CElayer and the second portion of the electrochromic CE layer have acombined thickness of about 270 nm.
 26. An electrochromic stack having asingle layer of metallic lithium disposed within the electrochromicstack, the electrochromic stack comprising: an electrochromic electrode(EC) layer; an electrochromic counter-electrode (CE) layer overlying theelectrochromic EC layer, the electrochromic CE layer including a firstportion and a second portion; a metallic lithium layer depositeddirectly over the first portion of the CE layer, wherein the metalliclithium layer is the only layer of the electrochromic stack depositedwith metallic lithium; and the second portion of the electrochromic CElayer is formed directly over the metallic lithium layer.
 27. Theelectrochromic stack of claim 26, wherein: the EC layer is formed fromdepositing the EC layer utilizing a lithium-containing ceramic electrodetarget.
 28. The electrochromic stack of claim 26, further comprising anion-conducting (IC) layer disposed between the electrochromic EC layerand the first portion of the electrochromic CE layer.
 29. Theelectrochromic stack of claim 26, wherein the first portion of theelectrochromic CE layer has a first thickness that is not less than 20nm, and wherein the first portion of the electrochromic CE layer and thesecond portion of the electrochromic CE layer have a combined thicknessof about 270 nm.
 30. The electrochromic stack of claim 26, wherein theCE layer comprises a NiWO_(x) material.
 31. An electrochromic stack,comprising: an electrochromic electrode (EC) layer formed fromdepositing the EC layer utilizing a lithium-containing ceramic electrodetarget; and an electrochromic counter-electrode (CE) layer overlying theelectrochromic EC layer, the CE layer formed from depositing the CElayer utilizing a lithium-containing ceramic counter-electrode target.32. The electrochromic stack of claim 31, further comprising anion-conducting (IC) layer disposed between the electrochromic EC layerand the electrochromic CE layer.
 33. The electrochromic stack of claim31, further comprising: a metallic lithium layer deposited over theelectrochromic EC layer, wherein the metallic lithium layer is the onlylayer of the electrochromic stack deposited with metallic lithium. 34.The electrochromic stack of claim 31, further comprising: a metalliclithium layer deposited over the electrochromic CE layer, wherein themetallic lithium layer is the only layer of the electrochromic stackdeposited with metallic lithium.
 35. The electrochromic stack of claim31, wherein the electrochromic stack includes no metallic lithium layer.36. An electrochromic stack having a single layer of metallic lithiumdisposed within the electrochromic stack, the electrochromic stackcomprising: an electrochromic electrode (EC) layer; an electrochromiccounter-electrode (CE) layer overlying EC layer; and a metallic lithiumlayer deposited between at least a portion of the electrochromic EClayer and the electrochromic CE layer, wherein the metallic lithiumlayer is the only layer of the electrochromic stack deposited withmetallic lithium.
 37. The electrochromic stack of claim 36, furthercomprising an ion-conducting (IC) layer disposed between theelectrochromic EC layer and the electrochromic CE layer.
 38. Theelectrochromic stack of claim 36, wherein: the electrochromic EC layerincludes a first portion and a second portion; the metallic lithiumlayer is deposited directly over the first portion of the electrochromicEC layer; and the second portion of the electrochromic EC layer isformed directly over the metallic lithium layer.
 39. The electrochromicstack of claim 38, further comprising an ion-conducting (IC) layerdisposed between the second portion of the electrochromic EC layer andthe electrochromic CE layer.
 40. The electrochromic stack of claim 38,wherein the first portion of the electrochromic EC layer has a firstthickness that is not less than 20 nm, and wherein the first portion ofthe electrochromic EC layer and the second portion of the electrochromicEC layer have a combined thickness of about 400 nm.